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1.
Molecules ; 28(17)2023 Sep 04.
Artículo en Inglés | MEDLINE | ID: mdl-37687261

RESUMEN

Currently, energy storage systems are of great importance in daily life due to our dependence on portable electronic devices and hybrid electric vehicles. Among these energy storage systems, hybrid supercapacitor devices, constructed from a battery-type positive electrode and a capacitor-type negative electrode, have attracted widespread interest due to their potential applications. In general, they have a high energy density, a long cycling life, high safety, and environmental friendliness. This review first addresses the recent developments in state-of-the-art electrode materials, the structural design of electrodes, and the optimization of electrode performance. Then we summarize the possible classification of hybrid supercapacitor devices, and their potential applications. Finally, the fundamental theoretical aspects, charge-storage mechanism, and future developing trends are discussed. This review is intended to provide future research directions for the next generation of high-performance energy storage devices.

2.
Pediatr Surg Int ; 37(6): 745-754, 2021 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-33538868

RESUMEN

PURPOSE: Postoperative adhesive bowel obstruction (ABO) is a common complication especially in complicated appendicitis. This study aimed to analyze the risk factors for ABO following appendectomy in children with complicated appendicitis, and establish a scoring model for predicting postoperative ABO and treatment option to relieve the obstruction. METHODS: From December 2014 to January 2020, all files of consecutive patients with complicated appendicitis underwent appendectomy were reviewed. Univariate and multivariate analyses were used to screen out the risk factors of postoperative ABO, and establish a scoring model for predicting postoperative ABO and surgical relief to relieve the obstruction. RESULTS: Of the 780 patients, 87 (11.2%) had ABO following appendectomy, including 27 who underwent surgical relief. Age ≤ 6 years, overweight and obesity, duration of symptoms ≥ 36 h, C-reactive protein ≥ 99 mg/L, duration of operation ≥ 60 min, intraoperative peritoneal lavage, and postoperative flatus time ≥ 20 h were independent risk factors for postoperative ABO. The final scoring model for postoperative ABO included factors above, and exhibited a high degree of discrimination (area under the curve [AUC]: 0.937; 95% confidence interval [CI] 0.913-0.960) corresponding to an optimal cut-off value of 6: 82.8% sensitivity, 92.6% specificity. Furthermore, the scoring model showed a sensitivity of 74.1% and a specificity of 91.7% for patients wo underwent surgical relief to relieve obstruction with the optimal cut-off value of 9. CONCLUSION: Risk factors for postoperative ABO should be taken seriously in children with complicated appendicitis. The scoring model is a novel but promising method to predict postoperative ABO and provide reference for clinical decision-making to relieve the obstruction.


Asunto(s)
Apendicectomía/efectos adversos , Obstrucción Intestinal/etiología , Complicaciones Posoperatorias , Adherencias Tisulares/complicaciones , Adolescente , Apendicitis/cirugía , Niño , Preescolar , Femenino , Humanos , Lactante , Laparoscopía/efectos adversos , Masculino , Factores de Riesgo
3.
Ann Diagn Pathol ; 49: 151633, 2020 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-32977235

RESUMEN

OBJECTIVES: We investigated whether serum tumor markers (STMs) represent a valuable noninvasive tool to predict epidermal growth factor receptor (EGFR) mutations in non-small cell lung cancer (NSCLC) patients. METHODS: A retrospective analysis was performed for 143 NSCLC patients at the Peking University International Hospital from December 2014 to December 2019. EGFR mutations in the tumor tissues were identified by amplification refractory mutation system-polymerase chain reaction (ARMS-PCR) and next generation sequencing (NGS). The relationships between EGFR mutation and several clinicopathological features were analyzed. RESULT: EGFR mutation were found more frequently in female (56.67%, P = 0.01), never-smokers (55.26%, P = 0.004), and those with lung adenocarcinoma (ADC) (52.17%, P < 0.001). The positive mutation rate for the EGFR gene were higher in the squamous cell carcinoma antigen (SCCA)group (≤1.5 ng/ml) and in the gastrin-releasing peptide precursor (preGRP) increased group (≥69.2 pg/ml), and this difference was statistically significant (P < 0.05). Univariate logistic regression analysis demonstrated that females (Odd ratio [OR]: 2.435, 95% confidence interval [CI]: 1.232, 4.813, P = 0.01) and never-smokers (OR = 0.370; CI = 0.186, 0.734; P = 0.004), lung adenocarcinoma patients (OR = 9.091; CI = 2.599, 21.800; P = 0.001), the SCC group (≤1.5 ng/ml) (OR = 0.331, CI = 0.120, 0.914; P = 0.033), and the preGRP group (≥69.2 pg/ml) (OR = 5.478, CI = 1.462, 20.528; P = 0.012) patients were risk factors for EGFR gene mutation. Multivariate logistic regression analysis demonstrated that lung ADC and proGRP elevation were independent risk factors for predicting EGFR gene positivity (P < 0.05). CONCLUSION: STMs are associated with mutant EGFR status and could be integrated with other clinical factors to facilitate the classification of EGFR mutation status among NSCLC patients.


Asunto(s)
Biomarcadores de Tumor/sangre , Carcinoma de Pulmón de Células no Pequeñas/genética , Neoplasias Pulmonares/genética , Anciano , Biomarcadores de Tumor/genética , Carcinoma de Pulmón de Células no Pequeñas/sangre , Receptores ErbB/genética , Femenino , Humanos , Neoplasias Pulmonares/sangre , Masculino , Persona de Mediana Edad , Mutación , Estudios Retrospectivos
4.
Cell Biol Int ; 41(1): 62-70, 2017 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-27862640

RESUMEN

Long non-coding (lncRNA) MALAT1 can be increased by hypoxia or ischemic limbs. Also, downregulation of MALAT1 contributes to reduction of cardiomyocyte apoptosis. However, the functional involvement of MALAT1 in myocardial ischemia-reperfusion (I/R) injury has not been defined. This study investigated the functional involvement of lncRNA-MALAT1 in cardioprotective effects of fentanyl. HL-1, a cardiac muscle cell line from the AT-1 mouse atrial cardiomyocyte tumor lineage was pre-treated with fentanyl and generated cell model of hypoxia-reoxygenation (H/R). Relative expression of MALAT1, miR-145, and Bnip3 mRNA in cells was determined by quantitative real-time PCR. Cardiomyocyte H/R injury was indicated by lactate dehydrogenase (LDH) release and cell apoptosis. The results showed that fentanyl abrogates expression of responsive gene for H/R and induces downregulation of MALAT1 and Bnip3 and upregulation of miR-145. We found that miR-145/Bnip3 pathway was negatively regulated by MALAT1 in H/R-HL-1 cell with or without fentanyl treatment. Moreover, both MALAT1 overexpression and miR-145 knockdown reverse cardioprotective effects of fentanyl, as indicated by increase in LDH release and cell apoptosis. The reversal effect of MALAT1 for fentanyl is confirmed in cardiac ischemia/reperfusion (I/R) mice. In summary, lncRNA-MALAT1 is sensitive to H/R injury and abrogates cardioprotective effects of Fentanyl by negatively regulating miR-145/Bnip3 pathway.


Asunto(s)
Cardiotónicos/uso terapéutico , Fentanilo/uso terapéutico , Daño por Reperfusión Miocárdica/tratamiento farmacológico , Daño por Reperfusión Miocárdica/genética , ARN Largo no Codificante/metabolismo , Animales , Línea Celular , Técnicas de Silenciamiento del Gen , Proteínas de la Membrana/genética , Proteínas de la Membrana/metabolismo , Ratones , MicroARNs/genética , MicroARNs/metabolismo , Proteínas Mitocondriales/genética , Proteínas Mitocondriales/metabolismo , Fenotipo , ARN Largo no Codificante/genética
5.
J Pept Sci ; 20(1): 7-19, 2014 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-24222478

RESUMEN

Neuromedin U (NMU) is an endogenous peptide implicated in the regulation of feeding, energy homeostasis, and glycemic control, which is being considered for the therapy of obesity and diabetes. A key liability of NMU as a therapeutic is its very short half-life in vivo. We show here that conjugation of NMU to human serum albumin (HSA) yields a compound with long circulatory half-life, which maintains full potency at both the peripheral and central NMU receptors. Initial attempts to conjugate NMU via the prevalent strategy of reacting a maleimide derivative of the peptide with the free thiol of Cys34 of HSA met with limited success, because the resulting conjugate was unstable in vivo. Use of a haloacetyl derivative of the peptide led instead to the formation of a metabolically stable conjugate. HSA-NMU displayed long-lasting, potent anorectic, and glucose-normalizing activity. When compared side by side with a previously described PEG conjugate, HSA-NMU proved superior on a molar basis. Collectively, our results reinforce the notion that NMU-based therapeutics are promising candidates for the treatment of obesity and diabetes.


Asunto(s)
Fármacos Antiobesidad/síntesis química , Hipoglucemiantes/síntesis química , Neuropéptidos/síntesis química , Neuropéptidos/farmacología , Polietilenglicoles/farmacología , Albúmina Sérica/síntesis química , Animales , Fármacos Antiobesidad/farmacocinética , Fármacos Antiobesidad/farmacología , Glucemia , Línea Celular , Evaluación Preclínica de Medicamentos , Humanos , Hipoglucemiantes/farmacocinética , Hipoglucemiantes/farmacología , Masculino , Ratones , Ratones Endogámicos C57BL , Neuropéptidos/farmacocinética , Polietilenglicoles/farmacocinética , Receptores de Neurotransmisores/agonistas , Albúmina Sérica/farmacocinética , Albúmina Sérica/farmacología , Albúmina Sérica Humana , Pérdida de Peso/efectos de los fármacos
6.
Zool Res ; 45(1): 39-54, 2024 Jan 18.
Artículo en Inglés | MEDLINE | ID: mdl-38114432

RESUMEN

The dynamics of animal social structures are heavily influenced by environmental patterns of competition and cooperation. In folivorous colobine primates, prevailing theories suggest that larger group sizes should be favored in rainforests with a year-round abundance of food, thereby reducing feeding competition. Yet, paradoxically, larger groups are frequently found in high-altitude or high-latitude montane ecosystems characterized by a seasonal scarcity of leaves. This contradiction is posited to arise from cooperative benefits in heterogeneous environments. To investigate this hypothesis, we carried out a six-year field study on two neighboring groups of golden snub-nosed monkey ( Rhinopithecus roxellana), a species representing the northernmost distribution of colobine primates. Results showed that the groups adjusted their movement and habitat selection in response to fluctuating climates and spatiotemporal variability of resources, indicative of a dynamic foraging strategy. Notably, during the cold, resource-scarce conditions in winter, the large group occupied food-rich habitats but did not exhibit significantly longer daily travel distances than the smaller neighboring group. Subsequently, we compiled an eco-behavioral dataset of 52 colobine species to explore their evolutionary trajectories. Analysis of this dataset suggested that the increase in group size may have evolved via home range expansion in response to the cold and heterogeneous climates found at higher altitudes or latitudes. Hence, we developed a multi-benefits framework to interpret the formation of larger groups by integrating environmental heterogeneity. In cold and diverse environments, even smaller groups require larger home ranges to meet their dynamic survival needs. The spatiotemporal distribution of high-quality resources within these expanded home ranges facilitates more frequent interactions between groups, thereby encouraging social aggregation into larger groups. This process enhances the benefits of collaborative actions and reproductive opportunities, while simultaneously optimizing travel costs through a dynamic foraging strategy.


Asunto(s)
Colobinae , Presbytini , Animales , Ecosistema , Colobinae/fisiología , Clima , China
7.
Am J Physiol Endocrinol Metab ; 303(2): E265-71, 2012 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-22621866

RESUMEN

Glucagon-like peptide-1 (GLP-1) and oxyntomodulin (OXM) are peptide hormones secreted postprandially from the gut that stimulate insulin secretion in a glucose-dependent manner. OXM activates both the GLP-1 receptor (GLP1R) and the glucagon receptor (GCGR). It has been suggested that OXM acutely modulates glucose metabolism solely through GLP1R agonism. Because OXM activates the GLP1R with lower affinity than GLP-1, we generated a peptide analog (Q→E, OXMQ3E) that does not exhibit glucagon receptor agonist activity but retains the same affinity as OXM for GLP1R. We compared the effects of OXM and OXMQ3E in a glucose tolerance test and, to better characterize the effect on glucose metabolism, we performed controlled infusions of OXM or OXMQ3E during a hyperglycemic clamp performed in wild-type, Glp1r(-/-), and Gcgr(-/-) mice. Our findings show that OXM, but not OXMQ3E, activates the GCGR in vivo. Second, OXM and OXMQ3E improve glucose tolerance following an acute glucose challenge and during a hyperglycemic clamp in mice. Finally, OXM infusion during a glucose clamp reduces the glucose infusion rate (GIR) despite a simultaneous increase in insulin levels in Glp1r(-/-) mice, whereas OXM and OXMQ3E increase GIR to a similar extent in Gcgr(-/-) mice. In conclusion, activation of the GCGR seems to partially attenuate the acute beneficial effects on glucose and contributes to the insulinotropic action of oxyntomodulin.


Asunto(s)
Péptido 1 Similar al Glucagón/farmacología , Glucosa/metabolismo , Oxintomodulina/farmacología , Animales , Glucemia/efectos de los fármacos , Receptor del Péptido 1 Similar al Glucagón , Técnica de Clampeo de la Glucosa , Prueba de Tolerancia a la Glucosa , Insulina/sangre , Masculino , Ratones , Ratones Endogámicos C57BL , Receptores de Glucagón/genética , Receptores de Glucagón/metabolismo
8.
Bioorg Med Chem ; 20(15): 4751-9, 2012 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-22771182

RESUMEN

Neuromedin U (NMU) is an endogenous peptide, whose role in the regulation of feeding and energy homeostasis is well documented. Two NMU receptors have been identified: NMUR1, expressed primarily in the periphery, and NMUR2, expressed predominantly in the brain. We recently demonstrated that acute peripheral administration of NMU exerts potent but acute anorectic activity and can improve glucose homeostasis, with both actions mediated by NMUR1. Here, we describe the development of a metabolically stable analog of NMU, based on derivatization of the native peptide with high molecular weight poly(ethylene) glycol (PEG) ('PEGylation'). PEG size, site of attachment, and conjugation chemistry were optimized, to yield an analog which displays robust and long-lasting anorectic activity and significant glucose-lowering activity in vivo. Studies in NMU receptor-deficient mice showed that PEG-NMU displays an expanded pharmacological profile, with the ability to engage NMUR2 in addition to NMUR1. In light of these data, PEGylated derivatives of NMU represent promising candidates for the treatment of obesity and diabetes.


Asunto(s)
Diabetes Mellitus Experimental/tratamiento farmacológico , Neuropéptidos/farmacología , Obesidad/tratamiento farmacológico , Polietilenglicoles/química , Receptores de Neurotransmisores/agonistas , Animales , Relación Dosis-Respuesta a Droga , Prueba de Tolerancia a la Glucosa , Humanos , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Neuropéptidos/administración & dosificación , Neuropéptidos/síntesis química , Polietilenglicoles/administración & dosificación , Polietilenglicoles/síntesis química , Polietilenglicoles/farmacología , Receptores de Neurotransmisores/deficiencia , Relación Estructura-Actividad
9.
Mol Cell Biol ; 24(19): 8437-46, 2004 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-15367665

RESUMEN

The Werner and Bloom syndromes are caused by loss-of-function mutations in WRN and BLM, respectively, which encode the RecQ family DNA helicases WRN and BLM, respectively. Persons with Werner syndrome displays premature aging of the skin, vasculature, reproductive system, and bone, and those with Bloom syndrome display more limited features of aging, including premature menopause; both syndromes involve genome instability and increased cancer. The proteins participate in recombinational repair of stalled replication forks or DNA breaks, but the precise functions of the proteins that prevent rapid aging are unknown. Accumulating evidence points to telomeres as targets of WRN and BLM, but the importance in vivo of the proteins in telomere biology has not been tested. We show that Wrn and Blm mutations each accentuate pathology in later-generation mice lacking the telomerase RNA template Terc, including acceleration of phenotypes characteristic of latest-generation Terc mutants. Furthermore, pathology not observed in Terc mutants but similar to that observed in Werner syndrome and Bloom syndrome, such as bone loss, was observed. The pathology was accompanied by enhanced telomere dysfunction, including end-to-end chromosome fusions and greater loss of telomere repeat DNA compared with Terc mutants. These findings indicate that telomere dysfunction may contribute to the pathogenesis of Werner syndrome and Bloom syndrome.


Asunto(s)
Síndrome de Bloom/metabolismo , Telómero/metabolismo , Síndrome de Werner/metabolismo , Animales , Síndrome de Bloom/genética , Constitución Corporal/genética , Constitución Corporal/fisiología , Infertilidad/genética , Infertilidad/metabolismo , Intestino Delgado/patología , Longevidad/genética , Longevidad/fisiología , Masculino , Ratones , Mutación , ARN/genética , ARN/metabolismo , Telomerasa/genética , Telomerasa/metabolismo , Telómero/genética , Testículo/patología , Síndrome de Werner/genética , Cicatrización de Heridas/genética , Cicatrización de Heridas/fisiología
10.
Artículo en Zh | MEDLINE | ID: mdl-16775408

RESUMEN

Basing on the fragment (CO434610) cloned from cDNA amplified fragment length polymorphism (cDNA-AFLP), a 1191-bp cDNA sequence of CsEXP10 with a complete 3' end was obtained via rapid amplification of cDNA ends (RACE) and getting spliced with an EST (AF319471) of the same gene (Fig.2). Southern blotting analysis showed that CsEXP10 was a single copy gene in cucumber (Fig.5). The transcripts of CsEXP10 were detected by RT-PCR only in young fruit 3 d after pollination, but not in root, stem, and leaf (Fig.4A). At different developmental stages of fruit growth, Northern blotting demonstrated that CsEXP10 gene was expressed strongly in fruit 3 d and 10 d after pollination, especially the latter, but undetectable in ovaries of 2-3 cm in length and without pollination on the day flowering, and in fruits 26 d after pollination (Fig.4B). It is suggested that CsEXP10 might be highly correlated with the expansive growth of cucumber fruit.


Asunto(s)
Cucumis sativus/genética , Frutas/genética , Proteínas de Plantas/genética , Secuencia de Aminoácidos , Secuencia de Bases , Northern Blotting , Southern Blotting , Clonación Molecular , Cucumis sativus/crecimiento & desarrollo , ADN Complementario/química , ADN Complementario/genética , Frutas/crecimiento & desarrollo , Regulación del Desarrollo de la Expresión Génica , Regulación de la Expresión Génica de las Plantas , Datos de Secuencia Molecular , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Análisis de Secuencia de ADN , Homología de Secuencia de Aminoácido
11.
Genes (Basel) ; 7(12)2016 Nov 30.
Artículo en Inglés | MEDLINE | ID: mdl-27916887

RESUMEN

We identified a novel member of the metallothionein (MT) family, Cucumis sativus metallothionein-like 2 (CsMTL2), by screening a young cucumber fruit complementary DNA (cDNA) library. The CsMTL2 encodes a putative 77-amino acid Class II MT protein that contains two cysteine (Cys)-rich domains separated by a Cys-free spacer region. We found that CsMTL2 expression was regulated by metal stress and was specifically induced by Cd2+ treatment. We investigated the metal-binding characteristics of CsMTL2 and its possible role in the homeostasis and/or detoxification of metals by heterologous overexpression in Escherichia coli cells. Furthermore, we produced a deletion mutant form of the protein, CsMTL2m, that contained the two Cys-rich clusters but lacked the spacer region, in E. coli. We compared the metal-binding properties of CsMTL2 with those of CsMTL2m, the ß domain of human metallothionein-like protein 1 (HsMTXb), and phytochelatin-like (PCL) heterologously expressed in E. coli using metal-binding assays. We found that E. coli cells expressing CsMTL2 accumulated the highest levels of Zn2+ and Cd2+ of the four transformed cell types, with levels being significantly higher than those of control cells containing empty vector. E. coli cells expressing CsMTL2 had a higher tolerance for cadmium than for zinc ions. These findings show that CsMTL2 improves metal tolerance when heterologously expressed in E. coli. Future studies should examine whether CsMTL2 improves metal tolerance in planta.

12.
Sheng Wu Gong Cheng Xue Bao ; 28(7): 823-33, 2012 Jul.
Artículo en Zh | MEDLINE | ID: mdl-23167194

RESUMEN

Studies on lycopene synthesis in Escherichia coli were not only able to gain the strains with high yield and less by-products, but also able to test functions of genes or gene clusters. In this article, the cDNA sequences of tomato LeGGPS2 and LePSY1 as well as the coding sequence of crtI from Erwinia uredovora, each of which was added a ribosome biding site, were controlled by T7 promoter and terminator alone or combined, and expressed in E. coli BL21 (DE3) to induce lycopene synthesis. The results show that only T7::crtI-LeGGPS2-LePSY1 expressed tri-cistronically could produce lycopene, and 2.124 mg/g dry cell weight oflycopene was obtained when fermented for 5 h at 30 degrees C after mixing 80 micromol/L IPTG at the later logarithmic phase while the seed broth of 1:50 (V/V) was inoculated into LB medium (pH 6.8) containing 3% sucrose and cultured for 8 h at 37 degrees C. The results confirmed the function of the prokaryonized LeGGPS2 and LePSY1 and their synergy with crtI, and also laid a foundation to establish an independent lycopene synthetic pathway in the tomato plastid.


Asunto(s)
Carotenoides/biosíntesis , Erwinia/genética , Escherichia coli/genética , Proteínas de Plantas/genética , Proteínas Bacterianas/genética , Carotenoides/genética , Clonación Molecular , Escherichia coli/metabolismo , Ingeniería Genética , Licopeno , Proteínas de Plantas/biosíntesis , Proteínas Recombinantes/biosíntesis , Proteínas Recombinantes/genética
13.
Endocrinology ; 152(7): 2644-54, 2011 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-21586559

RESUMEN

Neuromedin U (NMU) is a highly conserved peptide reported to modulate energy homeostasis. Pharmacological studies have shown that centrally administered NMU inhibits food intake, reduces body weight, and increases energy expenditure. NMU-deficient mice develop obesity, whereas transgenic mice overexpressing NMU become lean and hypophagic. Two high-affinity NMU receptors, NMUR1 and NMUR2, have been identified. NMUR1 is found primarily in the periphery and NMUR2 primarily in the brain, where it mediates the anorectic effects of centrally administered NMU. Given the broad expression pattern of NMU, we evaluated whether peripheral administration of NMU has effects on energy homeostasis. We observed that acute and chronic peripheral administration of NMU in rodents dose-dependently reduced food intake and body weight and that these effects required NMUR1. The anorectic effects of NMU appeared to be partly mediated by vagal afferents. NMU treatment also increased core body temperature and metabolic rate in mice, suggesting that peripheral NMU modulates energy expenditure. Additionally, peripheral administration of NMU significantly improved glucose excursion. Collectively, these data suggest that NMU functions as a peripheral regulator of energy and glucose homeostasis and the development of NMUR1 agonists may be an effective treatment for diabetes and obesity.


Asunto(s)
Metabolismo Energético , Intolerancia a la Glucosa/prevención & control , Neuropéptidos/fisiología , Animales , Regulación del Apetito , Metabolismo Basal , Regulación de la Temperatura Corporal , Diabetes Mellitus/tratamiento farmacológico , Preferencias Alimentarias , Isoenzimas/genética , Isoenzimas/metabolismo , Ratones , Ratones Endogámicos C57BL , Ratones Mutantes , Ratones Transgénicos , Terapia Molecular Dirigida , Neuropéptidos/administración & dosificación , Obesidad/tratamiento farmacológico , Ratas , Ratas Sprague-Dawley , Receptores de Neurotransmisores/genética , Receptores de Neurotransmisores/metabolismo , Pérdida de Peso
14.
J Med Chem ; 54(14): 5082-96, 2011 Jul 28.
Artículo en Inglés | MEDLINE | ID: mdl-21661758

RESUMEN

The potential use of SCD inhibitors for the chronic treatment of diabetes and dyslipidemia has been limited by preclinical adverse events associated with inhibition of SCD in skin and eye tissues. To establish a therapeutic window, we embarked on designing liver-targeted SCD inhibitors by utilizing molecular recognition by liver-specific organic anion transporting polypeptides (OATPs). In doing so, we set out to target the SCD inhibitor to the organ believed to be responsible for the therapeutic efficacy (liver) while minimizing its exposure in the tissues associated with mechanism-based SCD depletion of essential lubricating lipids (skin and eye). These efforts led to the discovery of MK-8245 (7), a potent, liver-targeted SCD inhibitor with preclinical antidiabetic and antidyslipidemic efficacy with a significantly improved therapeutic window.


Asunto(s)
Acetatos/síntesis química , Hipoglucemiantes/síntesis química , Hipolipemiantes/síntesis química , Hígado/enzimología , Estearoil-CoA Desaturasa/antagonistas & inhibidores , Tetrazoles/síntesis química , Acetatos/química , Acetatos/farmacología , Animales , Línea Celular , Difusión , Perros , Femenino , Glándula de Harder/metabolismo , Células Hep G2 , Hepatocitos/metabolismo , Humanos , Hipoglucemiantes/química , Hipoglucemiantes/farmacología , Hipolipemiantes/química , Hipolipemiantes/farmacología , Técnicas In Vitro , Transportador 1 de Anión Orgánico Específico del Hígado , Macaca mulatta , Masculino , Ratones , Ratones Endogámicos C57BL , Microsomas/metabolismo , Transportadores de Anión Orgánico/metabolismo , Transportadores de Anión Orgánico Sodio-Independiente/metabolismo , Ratas , Ratas Sprague-Dawley , Piel/metabolismo , Miembro 1B3 de la Familia de los Transportadores de Solutos de Aniones Orgánicos , Especificidad de la Especie , Relación Estructura-Actividad , Tetrazoles/química , Tetrazoles/farmacología , Distribución Tisular
15.
Appl Spectrosc ; 64(7): 781-5, 2010 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-20615292

RESUMEN

Silver nanorod (AgNR) array substrates are investigated to detect pure melamine dissolved in 50% methanol using surface-enhanced Raman spectroscopy (SERS). We find that sample preparation conditions have a great influence on melamine detection. When the samples are prepared under a nitrogen glove box, the SERS characteristic peak intensities of melamine at Deltanu = 497 cm(-1), 704 cm(-1), and 983 cm(-1) are studied as functions of melamine concentration and/or the mass of melamine. The peak intensities increase almost linearly when the melamine concentration increases from 0.1 mg/L to 10 mg/L and saturate when melamine concentration is greater than 50 mg/L. The bulk melamine limit of detection (LOD) is 0.1 mg/L, which is one order of magnitude less than the current standard. This study shows that AgNR based SERS detection can be used as a fast, highly sensitive, and quantitative detection method for melamine.

16.
Diabetes ; 58(10): 2258-66, 2009 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-19602537

RESUMEN

OBJECTIVE: Oxyntomodulin (OXM) is a glucagon-like peptide 1 (GLP-1) receptor (GLP1R)/glucagon receptor (GCGR) dual agonist peptide that reduces body weight in obese subjects through increased energy expenditure and decreased energy intake. The metabolic effects of OXM have been attributed primarily to GLP1R agonism. We examined whether a long acting GLP1R/GCGR dual agonist peptide exerts metabolic effects in diet-induced obese mice that are distinct from those obtained with a GLP1R-selective agonist. RESEARCH DESIGN AND METHODS: We developed a protease-resistant dual GLP1R/GCGR agonist, DualAG, and a corresponding GLP1R-selective agonist, GLPAG, matched for GLP1R agonist potency and pharmacokinetics. The metabolic effects of these two peptides with respect to weight loss, caloric reduction, glucose control, and lipid lowering, were compared upon chronic dosing in diet-induced obese (DIO) mice. Acute studies in DIO mice revealed metabolic pathways that were modulated independent of weight loss. Studies in Glp1r(-/-) and Gcgr(-/-) mice enabled delineation of the contribution of GLP1R versus GCGR activation to the pharmacology of DualAG. RESULTS: Peptide DualAG exhibits superior weight loss, lipid-lowering activity, and antihyperglycemic efficacy comparable to GLPAG. Improvements in plasma metabolic parameters including insulin, leptin, and adiponectin were more pronounced upon chronic treatment with DualAG than with GLPAG. Dual receptor agonism also increased fatty acid oxidation and reduced hepatic steatosis in DIO mice. The antiobesity effects of DualAG require activation of both GLP1R and GCGR. CONCLUSIONS: Sustained GLP1R/GCGR dual agonism reverses obesity in DIO mice and is a novel therapeutic approach to the treatment of obesity.


Asunto(s)
Péptido 1 Similar al Glucagón/farmacología , Obesidad/prevención & control , Oxintomodulina/uso terapéutico , Receptores de Glucagón/agonistas , Secuencia de Aminoácidos , Animales , Peso Corporal/efectos de los fármacos , Células CHO/efectos de los fármacos , Cricetinae , Cricetulus , Diabetes Mellitus Tipo 2/epidemiología , Diabetes Mellitus Tipo 2/prevención & control , Grasas de la Dieta/farmacología , Ingestión de Energía , Péptido 1 Similar al Glucagón/agonistas , Péptido 1 Similar al Glucagón/genética , Receptor del Péptido 1 Similar al Glucagón , Inyecciones Subcutáneas , Insulina/biosíntesis , Ratones , Ratones Endogámicos C57BL , Datos de Secuencia Molecular , Obesidad/inducido químicamente , Obesidad/complicaciones , Oxintomodulina/administración & dosificación , Receptores de Glucagón/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Pérdida de Peso/efectos de los fármacos
17.
J Biol Chem ; 280(17): 16909-15, 2005 Apr 29.
Artículo en Inglés | MEDLINE | ID: mdl-15722352

RESUMEN

Nucleotides, released from cells during inflammation and by mechanical stimulation, act through the P2 family of nucleotide receptors. Previous studies have demonstrated the expression of P2Y1 and P2Y2 receptors in osteoclasts. The aim of this study was to determine whether osteoclast P2Y receptors signal through NF-kappaB, a key transcription factor regulating osteoclastogenesis. Immunofluorescence was used to detect the p65 subunit of NF-kappaB, which upon activation translocates from the cytosol to nuclei. Low levels of NF-kappaB activation were observed in untreated rabbit osteoclasts and in those exposed to 2-methylthio ADP (P2Y1 agonist) or ATP or UTP (P2Y2 agonists). In contrast, UDP or INS48823 (P2Y6 agonists) induced a significant increase in the number of cells exhibiting NF-kappaB activation, a process sensitive to the proteasome inhibitor lactacystin. In osteoclasts purified by micromanipulation, reverse transcription-PCR revealed the presence of P2Y1, P2Y2, and P2Y6 receptor transcripts, and application of agonists for these receptors induced the transient rise of cytosolic calcium. Treatment of rat osteoclasts with UDP or INS48823, but not 2-methylthio ADP or UTP, increased osteoclast survival. Osteoprotegerin (a decoy receptor for RANK ligand) did not significantly alter the effects of UDP on NF-kappaB localization or osteoclast survival, consistent with a direct action. Moreover, SN50 (cell-permeable peptide inhibitor of NF-kappaB) suppressed the enhancement of cell survival induced by UDP and INS48823. Our findings demonstrate the presence of functional P2Y6 receptors in osteoclasts. Thus, nucleotides, following their release at sites of inflammation and mechanical stimulation, can act through P2Y6 receptors to initiate NF-kappaB signaling and enhance osteoclast survival.


Asunto(s)
FN-kappa B/metabolismo , Osteoclastos/citología , Osteoclastos/metabolismo , Receptores Purinérgicos P2/metabolismo , Uridina Trifosfato/análogos & derivados , Transporte Activo de Núcleo Celular , Adenosina Difosfato/metabolismo , Adenosina Trifosfato/metabolismo , Fosfatasa Alcalina/metabolismo , Animales , Huesos/metabolismo , Huesos/patología , Calcio/metabolismo , Núcleo Celular/metabolismo , Supervivencia Celular , Células Cultivadas , Citosol/metabolismo , Cartilla de ADN/farmacología , Relación Dosis-Respuesta a Droga , Inhibidores Enzimáticos/farmacología , Glicoproteínas/metabolismo , Inflamación , Ligandos , Microscopía Fluorescente , Osteoclastos/efectos de los fármacos , Osteoprotegerina , Inhibidores de Proteasoma , Agonistas del Receptor Purinérgico P2 , Conejos , Ratas , Ratas Wistar , Receptores Citoplasmáticos y Nucleares/metabolismo , Receptores Purinérgicos P2Y1 , Receptores Purinérgicos P2Y2 , Receptores del Factor de Necrosis Tumoral , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Transducción de Señal , Factores de Tiempo , Factor de Transcripción ReIA , Uridina Difosfato/metabolismo , Uridina Trifosfato/metabolismo , Uridina Trifosfato/farmacología
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